1887

Abstract

Summary

Western Venezuela is located in a complex deformation zone due to the Caribbean-South American plates interactions. Several models regarding the shallow and deep structure have been proposed, nevertheless, most of these studies are based on basin-scale observations. As a part of the GIAME project, new onland refraction profiles have been acquired across the Guyana Shield, the main orogenic belts, and the Caribbean allochtonous terranes, with a total length of ~2500 km of 2D seismic data. In this work, an analysis of a 560 km long profile is presented. The Northern Andes profile consists of 545 short-deployment seismometers, which recorded 13 land shots. The seismic data was used to generate a two-dimensional P-wave model showing velocities between 3.2-5.7 km/s for sedimentary covers; 6.1-6.5 km/s for upper crust, and 6.7 to 7.2, and 7.8 to 8.4 km/s for lower crust and upper mantle, respectively. The most prominent features imaged were a crustal thinning beneath the Falcón basin due to a previous history as a back-arc basin. In addition, lateral variability suggests collisional process related to suture zones between both Proterozoic and Paleozoic, and Paleozoic and Mesozoic-Cenozoic provinces. Finally, the Caribbean slab was observed in a low-angle subduction context beneath NW South America.

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/content/papers/10.3997/2214-4609.201801257
2018-06-11
2019-12-14
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References

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